src/third_party/trace-viewer/third_party/tvcm/third_party/Promises/reworked_APIs/IndexedDB/example/after.html

   1 <!DOCTYPE html>
   2 <html>
   3   <head>
   4     <title></title>
   5     <script>
   6       "use strict";
   7
   8       // Cribbed from:
   9       //   https://hacks.mozilla.org/2012/02/storing-images-and-files-in-indexeddb/
  10       var DB_NAME = "example";
  11       var OBJ_STORE_NAME = "objects";
  12       var VERSION = 1.0;
  13       var key = "thinger"
  14
  15       // Note that open() now returns a Future which resolves for open success.
  16       var f = this.indexedDB.open(DB_NAME, VERSION);
  17
  18       // Upgradeneeded is still an event since it's conditional (it isn't always
  19       // called and therefore can't be used to productively chain), so we
  20       // register it as such.
  21       f.onupgradeneeded = function(e) {
  22         console.log("database creation/upgrade needed");
  23         console.log("creating object store:", OBJ_STORE_NAME)
  24         e.target.result.createObjectStore(OBJ_STORE_NAME);
  25       };
  26
  27       // Now chain each step of our open/write/read process.
  28       f.then(function(db) {
  29         // We can only write once the DB is opened and upgraded/created.
  30         console.log("database opened successfully");
  31         console.log(db);
  32
  33         // Create a new Transaction in which to write and retun a future for
  34         // when the transaction opens.
  35         return db.transaction([OBJ_STORE_NAME], "readwrite").open();
  36       }).then(function(trans) {
  37         // Get the Object Store via the Transaction and write asynchronously
  38         return trans.objectStore(OBJ_STORE_NAME).put({ value: "stuff" }, key);
  39       }).then(function(transaction) {
  40           console.log("writing successful");
  41
  42           // Read it back
  43           return trans.objectStore(OBJ_STORE_NAME).get(key);
  44       }).done(function(value) { console.log("reading successful:", value); },
  45               function(e) { console.error("Failed with error:", e); }
  46       );
  47     </script>
  48   </head>
  49   <body></body>
  50 </html>